Japanese Patent Application laid-Open Publication No. 2005-44890 discloses a method for etching high-k dielectric films. The high-k dielectric films are used as gate insulating films of transistors and are expected to decrease current leakage to suppress more power consumption in comparison with conventionally used SiO2 films. However, processing techniques for fabricating the transistors, including removal of the high-k dielectric films, have not been fully established, and various methods are still in the research-and-development stage. As disclosed in Japanese Patent Application Laid-Open Publication No. 2005-44890, a high-k dielectric film containing Hf is dry-etched with a gas of BCl3, HBr, O2, fluorocarbon or the like, while a high-k dielectric film including La, Al or the like is wet-etched with a solution containing fluorinated acid and amine.